Greeter

Greeter service is a "hello world" service in the grpc world. The client and server source code can be found at: https://github.com/grpc/grpc-go

The assembled server in docker: https://github.com/bavix/greeter-server. Let's launch:

docker run -p 4770:4770 bavix/greeter-server -port=4770

The assembled client in docker: https://github.com/bavix/greeter-client. Let's launch:

docker run --network=host bavix/greeter-client -addr=127.0.0.1:4770 -name=gripmock

You should see the result of the client's work:

2023/09/09 06:00:11 Greeting: Hello gripmock

Terminate the service, let's run the same in docker-compose:

docker compose up

You should see stdout something like this:

 ✔ Container greeter-gripmock-server-1   Created                                                                                                                             0.0s 
 ✔ Container greeter-gripmock-greeter-1  Created                                                                                                                             0.0s 
Attaching to greeter-gripmock-greeter-1, greeter-gripmock-server-1
greeter-gripmock-server-1   | 2023/09/09 06:02:10 server listening at [::]:4770
greeter-gripmock-greeter-1  | 2023/09/09 06:02:10 Greeting: Hello gripmock
greeter-gripmock-server-1   | 2023/09/09 06:02:10 Received: gripmock
greeter-gripmock-greeter-1 exited with code 0

The server started successfully, and the client started and sent a request to the server. Afterwards the client completed its work with code 0.

Docker compose has the ability to interrupt the operation of containers if some service has stopped working. Typically, this mechanism is used in integration tests.

docker compose up --abort-on-container-exit --exit-code-from greeter

Now the result is like this:

 ✔ Container greeter-gripmock-server-1   Created                                                                                                                             0.0s 
 ✔ Container greeter-gripmock-greeter-1  Created                                                                                                                             0.0s 
Attaching to greeter-gripmock-greeter-1, greeter-gripmock-server-1
greeter-gripmock-server-1   | 2023/09/09 06:05:53 server listening at [::]:4770
greeter-gripmock-server-1   | 2023/09/09 06:05:53 Received: gripmock
greeter-gripmock-greeter-1  | 2023/09/09 06:05:53 Greeting: Hello gripmock
greeter-gripmock-greeter-1 exited with code 0
Aborting on container exit...
[+] Stopping 2/2
 ✔ Container greeter-gripmock-greeter-1  Stopped                                                                                                                             0.0s 
 ✔ Container greeter-gripmock-server-1   Stopped     

Using the gripmock service, we simulate the operation of a greeter server.

Create a stub stubs/greeter.yaml:

- service: Greeter
  method: SayHello
  input:
    equals:
      name: gripmock
  output:
    data:
      message: Hello, GripMock

Download the proto-file of the greeter service:

curl https://raw.githubusercontent.com/grpc/grpc-go/master/examples/helloworld/helloworld/helloworld.proto \
  --create-dirs -o api/helloworld.proto

Let's run gripmock:

docker run \
  -p 4770:4770 \
  -p 4771:4771 \
  -v ./api:/proto:ro \
  -v ./stubs:/stubs:ro \
  bavix/gripmock -stub=/stubs /proto/helloworld.proto

Let's launch the client:

docker run --network=host bavix/greeter-client -addr=127.0.0.1:4770 -name=gripmock

You should see the result of the client's work:

2023/09/09 06:16:10 Greeting: Hello, GripMock

In the docker-compose file it will look like this:

version: '3.8'

services:
  greeter:
    image: bavix/greeter-client:1
    depends_on:
      gripmock:
        condition: service_healthy
    command:
      - -addr=gripmock:4770
      - -name=gripmock
    networks:
      - bx-greeter

  gripmock:
    image: bavix/gripmock:2
    ports:
      - 4770:4770
      - 4771:4771
    healthcheck:
      test: "curl --connect-timeout 1 --silent --show-error --fail http://gripmock:4771/api/health/readiness"
      timeout: 1s
      interval: 1s
      start_period: 1s
      retries: 10
    command:
      - -stub=/stubs
      - /proto/helloworld.proto
    volumes:
      - ./stubs:/stubs:ro
      - ./api:/proto:ro
    networks:
      - bx-greeter

networks:
  bx-greeter:

Running an integration test:

docker compose -f docker-compose.test.yaml up --abort-on-container-exit --exit-code-from greeter

Result of running the integration test:

 ✔ Container greeter-gripmock-gripmock-1  Created                                                                                                                            0.0s 
 ✔ Container greeter-gripmock-greeter-1   Recreated                                                                                                                          0.0s 
Attaching to greeter-gripmock-greeter-1, greeter-gripmock-gripmock-1
greeter-gripmock-gripmock-1  | Starting GripMock
greeter-gripmock-gripmock-1  | Serving stub admin on http://:4771
greeter-gripmock-gripmock-1  | grpc server pid: 40
greeter-gripmock-gripmock-1  | Serving gRPC on tcp://:4770
greeter-gripmock-gripmock-1  | 172.20.0.2 - - [09/Sep/2023:07:45:05 +0000] "GET /api/health/readiness HTTP/1.1" 200 57
greeter-gripmock-gripmock-1  | 127.0.0.1 - - [09/Sep/2023:07:45:06 +0000] "POST /api/stubs/search HTTP/1.1" 200 50
greeter-gripmock-greeter-1   | 2023/09/09 07:45:06 Greeting: Hello, GripMock
greeter-gripmock-greeter-1 exited with code 0
Aborting on container exit...
[+] Stopping 2/2
 ✔ Container greeter-gripmock-greeter-1   Stopped                                                                                                                            0.0s 
 ✔ Container greeter-gripmock-gripmock-1  Stopped    

In the pipeline, you can operate with the code returned from docker compose and, if a non-zero value is received, mark the test as failed.

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